Check and update tcp dynamic port range

To check the TCP dynamic port range of Windows, we can perform netsh int ipv4 show dynamicportrange tcp to show how many ports for dynamic ports.

Why do we need to care about the TCP dynamic port range?

If the dynamic network ports are exhausted, it will not be able to establish any outbound network connection.

How do we check the dynamic port exhaustion?

We can perform netstat -ano -p tcp to check the port exhaustion by which process.

To check the port range, we can perform netsh int ipv4 set dynamicport tcp start=10000 num=55535 to update the dynamic port range. The Windows take the updated dynamic port range immediately and It is required to reboot.

To change to default, we can perform netsh int ipv4 set dynamicport tcp start=49152 num=16384 to update it.

Ref:

Detecting ephemeral port exhaustion

Port Exhaustion and You (or, why the Netstat tool is your friend)

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